The global cooling caused by these high carbon clouds wouldn't be as
catastrophic as a superpower-versus-superpower nuclear winter, but "the
effects would still be regarded as leading to unprecedented climate
change," research physical scientist Luke Oman said during a press briefing Friday at a meeting of the American Association for the Advancement of Science in Washington, D.C.

Earth is currently in a long-term warming trend.
After a regional nuclear war, though, average global temperatures would
drop by 2.25 degrees F (1.25 degrees C) for two to three years
afterward, the models suggest.

At the extreme, the tropics,
Europe, Asia, and Alaska would cool by 5.4 to 7.2 degrees F (3 to 4
degrees C), according to the models. Parts of the Arctic and Antarctic
would actually warm a bit, due to shifted wind and ocean-circulation
patterns, the researchers said.

After ten years, average global
temperatures would still be 0.9 degree F (0.5 degree C) lower than
before the nuclear war, the models predict.